If you're playing a false 9 with Spain, then Cesc over Silva, everytime. The former's greater off-ball intelligence and finishing would better fulfil such a role.
Also, Xavi and Iniesta is one entity. Each one wouldn't be able to operate without the other, as efficiently. You can't compare the two, as they 're players with diff skill sets and diff roles in the team. Yet they operate in complete unison and harmony, and that's the beauty of it.
But, while Iniesta 's role can be performed by a Messi/Silva to a respectful degree. What Xavi does, can't be replicated, not by Iniesta, not by anyone at this moment. Him pulling the strings in the middle, distributing play, setting the rhythm of the game and providing the platform/conditions for others to shine and in the manner in which he does. Such a Midfield authority and regality is currently unmatched. Players like him don't receive as much plaudits as their more flashy counterparts. But they are the true kings of an empire. There is a reason, y he's played every Spain game, every Barca game, and he's played even while carrying an injury. There is a reason, y Messi suffers with Argentina. And NO, Iniesta won't fix it!. I'd choose the commander over his deputies, the man who actually makes things tick. To paraphrase him, the man who manufactures Ballon d'Ors. I'd pick Xavi over Iniesta, and Messi...there is no debate here, and shouldn't be.
I think i got a bit emotional there. But i can't thank him enough for his services to my club, more importantly his services to this beautiful game. After all, its players like him who make it beautiful.